May 24: PDS Tornado Watch #356

THE NWS STORM PREDICTION CENTER HAS ISSUED A
   TORNADO WATCH FOR PORTIONS OF 
   
          WESTERN AND CENTRAL OKLAHOMA
          NORTHWEST AND NORTH-CENTRAL TEXAS
   
   EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL
   1000 PM CDT.
   
   ...THIS IS A PARTICULARLY DANGEROUS SITUATION...
   
   DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER...
   THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE
   POSSIBLE IN THESE AREAS.
   
   THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
   MILES EAST AND WEST OF A LINE FROM 45 MILES WEST NORTHWEST OF
   PONCA CITY OKLAHOMA TO 25 MILES SOUTH SOUTHWEST OF FORT WORTH
   TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
   WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).
   
   REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
   TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
   AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
   THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
   AND POSSIBLE WARNINGS.
   
   OTHER WATCH INFORMATION...CONTINUE...WW 352...WW 354...WW 355...
   
   DISCUSSION...TSTM INITIATION IS ANTICIPATED WITHIN THE NEXT HOUR OR
   TWO ALONG THE DRYLINE FROM WRN OK INTO W-CNTRL TX.  STRONG HEIGHT
   FALLS/DYNAMIC FORCING FOR ASCENT ASSOCIATED WITH NEGATIVELY TILTED
   MIDLEVEL TROUGH EMERGING INTO THE PLAINS SHOULD SUPPORT A RAPID
   INCREASE IN STORM COVERAGE THROUGH THE AFTERNOON.  WARM SECTOR AIR
   MASS IS CHARACTERIZED BY A VERY MOIST BOUNDARY LAYER WITH DEWPOINTS
   IN THE UPPER 60S TO LOWER 70S.  WHEN COUPLED WITH STEEP MIDLEVEL
   LAPSE RATES...ENVIRONMENT IS MODERATELY TO STRONGLY UNSTABLE WITH
   MLCAPE VALUES OF 2500-4000 J/KG.  DEEP-LAYER SHEAR STRENGTHENING TO
   40-50 KT WILL PROMOTE RAPID SUPERCELL DEVELOPMENT WITH THE INITIAL
   HAZARD BEING VERY LARGE HAIL.  INITIAL VEER-BACK WIND PROFILE
   OBSERVED IN CURRENT VADS/PROFILERS IS EXPECTED TO TRANSITION TO
   LARGE CLOCKWISE CURVED HODOGRAPHS BY 00Z WHERE 0-1 KM SRH WILL
   APPROACH 400-500 M2/S2.  AS SUCH...EXPECT A RAPID INCREASE IN THE
   THREAT FOR TORNADOES THIS AFTERNOON INTO EVENING...SOME OF WHICH
   COULD BE LONG-TRACKED AND STRONG TO VIOLENT.
   
   AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
   SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
   WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
   550. MEAN STORM MOTION VECTOR 23035.